The invention relates to a directly controlled and proportionally adjustable pressure limiting valve achieved by the below described embodiments.
The like pressure limiting valves are employed, e.g., as proportionally adjustable pressure limiting valves. In WO 00/50794 A1 a directly controlled pressure limiting valve is disclosed where an armature of a proportional solenoid acts on a valve cone through the intermediary of a tappet. The valve cone is slidingly guided in the valve housing, while the tappet contacting the valve cone is supported in the armature and extends through a guide disc of the valve housing. It is a problem in this solution that in a case of axial offset between the valve seat and the valve cone there is a possibility of the pressure limiting valve not reliably closing any more.
In DE 196 25 349 a solution improved in this respect is proposed, wherein the valve cone is supported directly in the armature. To this end, the armature is provided with a through bore closed on its rear side by a disc on which the valve cone is supported through the intermediary of a sphere. The valve cone is guided in the armature with a certain radial play, so that an axial offset between the armature and the valve cone may be compensated by a slight oblique position of the valve cone.
A similar solution is also disclosed in DE 32 44 840 C2.